The human skeleton has evolved to allow for upright posture and bipedal motion. The human spine in its development to support the upright body has developed areas of stress particularly at the base of the neck, the apex of the mid back (thoracic spine) and in the lower back (lower lumbar spine). The spine is formed by bony elements, the vertebrae, and cushions between vertebrae, the intervertebral discs. The spine is then supported by ligaments, fibrous bands of tissue that join bones together, and muscles and fascia, which provide dynamic support and zygapophyseal joints, two at each level posteriorly which join the vertebrae together. Anteriorly the intervertebral disc serves as a cushion between the vertebrae but also helps join the vertebrae together and provides stability.
When neck or back pain becomes chronic, usually due to injury or repetitive stress, and the pain becomes severe and limiting or disabling the intervertebral disc(s) is/are the source of pain.
The most common cause of disability below the age of forty-five is chronic low back pain. Chronic low back pain is due to intervertebral disc disease in forty percent of patients, zygapophyseal joint dysfunction is fifteen to thirty percent of patients, sacra-iliac joint complex dysfunction in fifteen percent of patients, and in the remaining fifteen percent, multiple causes.
When an intervertebral disc becomes injured, the natural reparative process is often hindered due to limited blood supply to the inner portion of the intervertebral disc. Normally blood vessels are found only in the outer third of the peripheral portion of the disc, the annulus. However nutrition to the central portion of the disc depends upon perfusion of nutrients through the vertebral end-plate which separates the disc from the body of the vertebra above and below.
When nutrition becomes impaired the disc tissue becomes acidic and a degenerative process usually ensues. If the normal reparative process is inadequate, the disc can continue to degenerate and be the source of pain. The degenerative process varies in extent in every intervertebral disc that is chronically painful. A chemical reaction occurs within the disc usually at the site of injury. The chemicals cause further breakdown of the disc and when the chemicals escape into the spinal canal inflammation occurs and affects the spinal nerves causing further pain. In older patients (35 years plus) where degeneration is present the pain is not only due to a chemical reaction within the disc but instability of the disc secondary to previous degeneration.
Low back pain is reaching epidemic proportions in the Western world. Traditionally the treatment for severe discogenic pain has been surgical removal of the injured intervertebral disc and fusion of the spine surgically by replacing the disc with bone graft or various metal implants containing bone graft. This procedure is very expensive. Costs can range up to one hundred thousand dollars. It requires from six months to one year to recover. Up to eighty percent of the fusions become solid. However pain improvement is problematical. At best fifty to sixty percent of patients experience pain reduction, not always completely. Up to fifty percent remain with the same degree of pain or worse. The latter group often becomes permanently disabled and dependent upon opioid medications.
Upon evaluation of back pain many factors must be considered: age, severity of pain, radiation of pain into buttock or legs, and the presence of leg numbness or weakness. Commonly most patients who suffer an initial injury can recover fully if they rest appropriately, and inflammation within or about the disc is addressed. Thereafter a conditioning program becomes important in order to strengthen the muscles for supporting the trunk and providing controlled movement. When there is recurrence of low back pain after injury or stress the condition usually becomes more serious.
When an intervertebral disc can be identified as a source of pain usually by combination of a MRI scan of the lumbar spine as well as lumbar discography, the latter is a provocative test for discogenic pain by placing a needle into the center of the disc and injection of radiographic contrast under pressure. In a normal disc there is no pain provoked. In an abnormal disc pain is provoked, and if it causes the pain that is experienced by the patient, then the disc is concordantly painful.
At the same time fissures to the outer portion of the disc, the annulus, or multiple tears radiating from the center of the disc, the nucleus, to the periphery of the disc through the annulus are visualized. If the intervertebral disc has normal height, and there is a single fissure, and there is severe pain on low pressure by discogram, then a highly chemically sensitive disc is present. This condition is called an internal disc disruption. If multiple tears are identified, the disc has become narrowed by degeneration, and the pain is less severe but still significant, the condition is often called symptomatic degenerative disc disease.
The traditional treatment to the present time for severe painful discogenic disease has been spinal fusion. Successful results are modest. Therefore it is essential to find simpler and better ways to treat painful intervertebral discs. Several devices have been developed in recent years. At present there are two devices that are used relatively commonly, the first is the IDET (intra-discal electrothermal therapy) and the other is the nucleoplasty.
These two devices have limited use. They can only be used on intervertebral discs that have nearly normal height, have a single fissure and are chemically sensitive. The nucleoplasty is also used when there is posterior bulging of the disc for it will remove or ease the central pressures within the disc and therefore the pressure upon the periphery of the disc is reduced. Their success is partial. No alternative treatment for internal disc disruption or symptomatic degenerative disc disease has been developed until the chemical disc injection treatment (disc restorative solution) of this invention.